This is the extended version of the artifact analysis at the end of my visual discourse analysis.
This artifact illustrates the stratigraphic column of the Grand Canyon. It illustrates the ages, relative ages, and types of formations in the area. The different textures show the different types of stone found there. These textures are universal, so the graphic can be understood by any geologist. For example, the brick pattern seen in the Redwall Limestone and Kaibab formation indicates the formations are made of limestone, whereas the dots the Manakacha and Wescogame Formations indicate sandstone. Different types of rocks have different patterns. Following the law of superposition, the oldest formation, Vishnu Schist, is at the bottom, while the Chinle formation is the youngest.
Eliot Burress RC 2001 